I. Field of the Invention
The invention relates generally to toothbrushes, and more particularly, to toothbrushes having two brush heads arranged to provide for more efficient cleaning of the user's teeth and gums.
II. Description of the Prior Art
Various prior art toothbrushes have been proposed to provide for more efficient cleaning of the user's teeth and gums. Typical and pertinent examples of such toothbrushes, including examples of toothbrushes having two brush heads, are included in the following U.S. Pat. Nos.:
Levin 1,913,990 issued June 13, 1933 PA1 Fitzgerald 2,153,554 issued Apr. 11, 1939 PA1 Meeske 2,229,664 issued Jan. 28, 1941 PA1 Seko 2,651,068 issued Sept. 8, 1953 PA1 Gracian 2,978,724 issued Apr. 11, 1961 PA1 Soleymani 3,474,481 issued Oct. 28, 1969
Despite the design of numerous prior art toothbrushes which have attempted to provide for more efficient cleaning of the user's teeth, there still exists the problem of inadequate removal of plaque from the concave surfaces of at least some of the user's teeth. Such inadequate removal of plaque results in tooth decay, and gum or periodontal disease. The incidence of such tooth decay and gum disease is found by dentists to be widely prevalent, notwithstanding the fact that at least some of the unfortunate patients do regularly brush with conventionally designed or standard design toothbrushes available today.
While various prior art toothbrush designs have been proposed, the "standard design" toothbrush which has evolved basically consists of a brush with a straight handle having a brush head with bristles set in a rectangular configuration. Prior art toothbrushes and such standard design toothbrushes do not lend themselves effectively to cleaning the lingual surfaces of the anterior teeth because the generally long flat arrangement of the rectangular bristle configuration will not fit into the curved areas directly behind the anterior teeth, either on the top or bottom of the user's mouth. The present day manufacturers' attempt to overcome this inadequacy by advising the users to place the "toe" or outer edge of the brush into these areas to clean them. This requires a very difficult and clumsy maneuver by the patient and as a result the areas are not cleaned.
As a result of inadequate cleaning, calculus or tartar is generally formed in the concave region behind the six lower front teeth. This area always contains a pool of saliva and the calcium and phosphorus in the saliva precipitates out into the old plaque which is left on the teeth in this area (old plaque refers to plaque which has remained on the teeth for some period of time in excess of 24 hours and has become more firmly affixed to the teeth). When this precipitation occurs calculus forms, and it provides a porous surface for new plaque to attach to. A fresh layer of plaque becomes active here, producing acids and irritants to cause decay and gum disease, respectively.
Soon this plaque becomes calculus and another layer of plaque forms, on and on until the teeth are firmly entrenched in a covering of calculus. This results in local infection and irritation of the attachment apparatus or ligaments of the teeth, and periodontal disease sets in. All this occurs while the patient may be brushing the front surfaces of the teeth fairly adequately, but the damage goes on undetected on the lingual or concave back surface of the lower front teeth.
Another problem area is the back or lingual portion of the upper anterior or front teeth. This area is located and curved in such a way as to make the use of a prior art or standard toothbrush very difficult. The straight line rectangular bristle configuration of a standard toothbrush makes cleaning the lingual concave surfaces of these teeth almost impossible and the gum line area even more difficult. The patient cannot see this surface of the teeth and if they are to try, as the general advice from most brush manufacturers goes, to use the "toe" of the brush, their effectiveness here is strictly and severely limited.
In summary, despite the design of numerous prior art toothbrushes which have attempted to provide for more efficient cleaning of the user's teeth, such prior art toothbrushes have been found to be lacking in providing a toothbrush which can be used for removing plaque from all of the user's teeth. Specifically, such prior art toothbrushes have not provided the user with two brush heads having convex bristle surfaces which are designed and arranged to be comfortable, and which are easy to selectively use for efficiently removing plaque which forms on the concave lingual surfaces of the upper and lower teeth, and on the concave surfaces of all of the user's other teeth.
This invention is concerned with this general area and has among its objects to provide a toothbrush which avoids some or all of the inadequacies of the prior art.
Another more particular object of the present invention is to provide a toothbrush which is simple and economical to manufacture, and which is designed to cooperate with the user's hand, mouth and teeth so as to be comfortable and easy to use, while still providing for efficient removal of plaque from the user's teeth, thus insuring its more regular and thorough use.
A still more particular object of the present invention is to provide such a toothbrush which includes two brush heads having convex bristle surfaces designed and arranged so that plaque can be efficiently removed from the lingual and other concave surfaces of all of the user's teeth and gums.